High-speed register



Nov. 13,A 1962 w. K. GANNETT 3,063,633

HIGH-SPEED REGISTER Filed Dec. 9, 1958 2 Sheets-Sheet 1 l k h- X1 Nov. 13, 1962 uw. K. GANNl-:TT 3,063,633

HIGH-SPEED REGISTER Filed Dec. 9, 1958 2 Sheets-Sheet 2 Patented Nov. I3, 1952 3,063,633 HIGH-SPEED REGISTER WrightpK. Gannett, Davenport, Iowa, assignor to Mast Development Co.,` Davenport, Iowa Filed Dec. 9, 1958, Ser. No. 780,658 27 Claims. (Cl. 23S-103) The present invention relates yto a counting mechanism in which a rotating-shaft input is converted into a visual, counter-type, numeral-display output.

The principal object of this invention is to provide a reversible mechanical counter of extreme high speed, on the order of 2,500 counts per second or 150,000 counts per minute and having exceptional reliability under severe ambient and use conditions. A further object is to provide a counter characterized by compactness and possessing extreme reliability even where the speed of kcount is low. These objectives are obtained by the elimination of indexing mechanisms, while keeping something like the appearance of indexing in the numeral display.V This is done by moving a mask over the numeral or oli" the numeral rather than bymoving the'numeral'out of or into thedisplayarea. The interactionan'd cooperation of continuously moving masks with Vcontinuously moving numeral displays produce this eliect. Another object is to simulate in the numeral display the action ofthe numeral displays of various types of orthodox counters.

FIGURE l is a perspective of the basic movable components of one form of the invention, with the masks and knumerals shown in mid-transfer position.

i FIGURE 2 is a plan View of FIGURE 1, with` aportion of `a fixedwindowadded but broken away to avoid `covering too much lof the adjacent detail and the masks and numerals are 'again shown at mid-transfer position.

FIGURE 3 is an end view of FIGURE Zandwshows direction of rotation for increasing count.l

FIGURE 4 is a diagrammatic perspective of the opaque masks carried by the basic tube, but this tube is here turned 90 about its cylindrical axis from its position in FIGURE 1 to show the masks more clearly.

FIGURE 5 is a perspective of the display mask.

FIGURE 6 is a rplan view of the display mask, showing how this mask covers certain numerals while displaying others in an associated numeral band.

FIGURE 7 shows the numeral'band extended and illustrates schematically the relationship Vof the openings in the display mask to the numerals on the band.

FIGURE 8 is a perspective of a modified cylindrical display mask.

FIGURE 9 is an end-view of FIGURE 8 with portions of associated parts added.

FIGURE 10 shows an, optical means for giving the numerals in the right hand wheel the appearance of indexing for certain situations which require this feature.

FIGURES 11, l2 and 13 are respectively like FIGURES 1, 2 and 3 but show a modified mechanism.

FIGURE 14 is a diagrammatic perspective of the opaque masks carried by the tubes of FIGURES 1l, 12 and 13 and are turned 60 about their cylindrical axes from their position in FIGURE 11 to show the masks more clearly.

FIGURE 15 is a plan view of the display mask of FIGURES 11, 12 and 13, showing how it covers certain numerals while displaying others in an associated numeral band.

FIGURE 16 is a plan view vof the multiple coils of the numeral band of FIGURES l1, 12 and 13.

FIGURE 17 shows the numeral band extended and shows schematically the relationship of the openings in the displayV mask to the numerals on the band.

FIGURE 18 shows the band in exploded cabinet-projectiony relationship to the display mask in FIGURE 1l.

FIGURE 19 shows the band in elevation.

FIGURE 20 is a schematic elevation of the band and its supporting sprockets.

VFIGURE 21 is a schematic perspective showing how this 'four-digit register can be converted to a three-digit register by eliminating the multiple-loop display of FIG- URE 7 and by changing the drum-type display mask of FIGURE 15 to a drum-type numeral Wheel.

FIGURE 22 is a schematic illustration of typical drive means and support structure for the register components.

In all tigures the numeral wheels (or bands) and masks are driven at a uniform speed for a uniform speed of the input 50, as will appear below. That is, a geared (or gearequivalent) relationship exists among all moving parts. There are no indexing or intermittent mechanisms in this train of mechanism. All moving members move with s'pecilic ratios to the input as called out later in the detailed description. This gearing may be of any suitable form to obtain the necessary mechanization and is shown separately in FIGURE 22 to avoid obscuring the other figures.

The figures are drawn in a certain manner intended to kbring out the operating principles of the essential counting'mechanisms and in this respect it is important to note the following:

FIGURES 1, 2, 3 are projectively related as central section, plan and end views, respectively, with the exceptions that'FIGURE l is longer and on the right hand end to separate the components for clarity and is expanded in cabinet or cavalier projection to make the components kappear as if in three dimensions.

VFIGURES l1, 12, 13 are projectively related as central (elevation) section, plan, and end views respectively, with the exceptions that FIGURE 11 is expanded in cabinet or`cavalier projection to make the components appear as if in three dimensions and is longer on the right hand end to separate the components for clarity.

In all figures, the standard numeral positions are designated by the letters A, B, C and D for the digits, tens, hundreds and thousands positions, respectively.

The detailed description of the mechanism of FIG- URES 1-9 follows. This form of the invention is distinguished by the fact that a single-loop numeral band or indicia means 7 carries the numerals in the B and C positions. The advantages of this mechanism are that it is simple and has a long excursion in the D and C positions, thereby adapting it to such applications as a degreeof-arc counter, a mil angle counter, and a four-digit counter cycling in a 10,000 count.

It is to be understood that the mechanism-s described are illustrative only and may be departed from without violating the spirit of this invention. It is to be further understood that a number base other than ten might be .used in the numeral display.

A cylindrical tube 1 rotates on centers Si on the axis of the cylinder and is driven by the input 50, to which it is coaxially keyed or otherwise attixed (FIGURE 22). The tube 1 carries two consecutive series of ten indicating marks, here numerals (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, l, 2, 3, 4, 5, 6, 7, 8, 9) about its outer circumference. Preferably the tube 1 is a transparent cylinder opaqued in certain areas for purposes to presently appear. It may be opaqued in the area of the numerals to improve the legibility of the numerals by preventing the viewing of other parts Within the tube. This type of design avoids the necessity of cutting slots, etc., which would be required if a solid opaque tube were used. The zone or portion of the tube 1 that carries these numerals constitutes a wheel means 2, which is in the A position (the digit wheel of the usual four-digit counter). The wheel 2 does not index and hence may be regarded as being in continuous, one-count transfer; i.e., one new numeral is moved into position for each one count. The direction of rotation shown (FIGURES 1 and 3) is for increasing count, but rotation may be either way: for increasing or for decreasing count. Since this wheel 2 is in continuous motion it resembles the odometer in an automobile and hence does not in this respect resemble other counters in which the position A wheel indexes. The wheel Z is viewed through a stationary part of the basic support which may include any opaque frame affording a window 4 closely adjacent to the wheel 2 so as to minimize parallax. This wheel may carry graduations at and between numerals and these are read against a reader mark or reference zone 5 on the window 4. A separate wheel 3 is disposed within the tube 1 in the B position (the tens wheel of a normal four-digit counter) and turns on a cross shaft 54 normal to the axis of the tube 1 and carried by a stationary internal support or framework 52 to which the stationary mask or window 4 is afiixed as at 53 (FIGURE 22). This framework is of such construction that it extends down the bore of the tube 1 through the bore of the left hand bearing 51 to effect the connection at 53 to` the mask or window 4.

The wheel 3 is driven from the input 50v as by pinions 55, a worm 56 and a worm wheel 57, the latter being coaxially fixed to the wheel 3. The wheel 3 carries one cycle of indicating marks or numerals and is driven so that it turns at a speed of one numeral per every one series of numerals on wheel 2. As seen in FIGURE 3 the rim of the wheel 3 in the viewing area is curved so as to lie closely concentric with the axis of the tube 1 and this rirn mates at minimum clearance with a torus-like groove 6a on the inside surface of the tube 1. The width of this groove is suthcient to span at least two numerals on wheel 3. The purpose of mating the surface and groove is to minimize parallax between the numerals on the rim of wheel 3 and a transfer and display means 6, including mask portions bordering and defining a window portion carried on the inner surface of groove 6a. The means 6 (FIGURES l, 2 and 4) is a transparent circumferential opening in the otherwise opaqued groove 6a. That is to say, the transparent opening is bordered by opaqued edges shaped to make this opening essentially helical so that it can follow the motion of a numeral on wheel 3 in essentially a thread-and-tooth relationship. Thus means 6 may be regarded as an internal thread of a hollow worm, while the numeral on the wheel 3 may be considered as the space between teeth on a worm wheel. The purpose cf the means 6 is to uncover a succeeding or new numeral and to cover the preceding or old numeral on the wheel 3 whereby transfer occurs. The means 6 is shown at mid-transfer in FIGURE 2. The transfer is shown between numerals 9 and 0 rather than between two other numerals in order that transfer at all numeral positions (DC, B, A) may be shown simultaneously. In FIGURE 2 the mid-transfer condition shows half of each numeral displayed and half covered. The helical nature of the transfer and display or mask and window means 6 is such that it comprises two semicircular parts or helical portions offset at their meeting as best seen in FIGURE 4. Thus the two parts or series of this mask and window means accord with the two series of numerals on the wheel 2. Stated otherwise, the individual series of the means 6 (FIGURES 1 and 4) may be regarded as successive 180 portions of the individual threads of a two-thread worm. The beginning and end points of the series of the means 6 occur at the same time as the beginning and end points of the series on the wheel 2. If the DC, B, A numerals are all read in a straight line (as they are in FIGURE 2) then the end points of the series on the wheel 2 and on the means d are synchronized as to angular position as well as to time. The position is measured angularly about the axis of tube 1. The end point of each series on the wheel 2 is defined as midway between adjacent numerals 9 and 0. As shown in FIGURE 2 this is also midway in the transfer status of the means 6. Transfer is accomplished by the transit of the series-end points or divisions in the means 6 across the width W (FIGURE 2) in the window 4 which is elongated to the left of the A position so as to overlap or include the B, C and D positions. Since there are two series in the means 6 there are two transfers between the means l6 and the wheel 3 in one revolution of the tube 1.

It is axiomatic in the design of a single (not cascaded) mechanical counter that transfer at all numeral positions should take place in essentially the same amount of time (duration). This generally will be the duration of transfer of the wheel in the A position. Thus if the A transfer occurs in l/ 2500 of a second, all positions must transfer in 1/2500 of a second even though they transfer less frequently. 4If this rule is not followed the correct count will not register all of the time during transfer, because the faster transfer positions will register the new numeral while the slower transfer positions still register the old numeral. In the mechanism of FIGURES 1 9 the A- position wheel 2, like that of an odometer, does not index and hence can be regarded as using the entire one count between numerals for transfer-in short, one-count transfer. The wheel 3 transfers at the end of each 180 of rotation of the wheel 2. This transfer is accomplished in one count, provided that the angular width of W is equal to the angular width of one numeral space on the wheel 2. Reading of the register is made easier and clearer if W is slightly larger than the pitch between adjacent numerals on the wheel 2. However FIGURE 2 shows just the opposite to favor the description of FIGURE 10.

It is important here to digress briefly and establish clearly the difference between the duration of transfer and the frequency (commonly called speed) of transfer. Thus, with one-count transfer the numerals at all positions transfer at a duration which is the reciprocal of the counting speed. Example: the duration of transfer is 3%250@ of a second for a counting speed of 2500 c.p.s. (counts per second) for the mechanism shown in FIG- URES 1-9 where the wheel 2 does not index. But the frequency of transfer in the above example is 2500 per second in position A, 250 per second in position B, and 25 per second in positions C and D. In a normal fourdigit counter the frequency of transfer at position D would be 2.5 per second, but D is caused to transfer with C for reasons to be brought out later.

In an orthodox indexing counter the dynamics problems at each wheel position are predominantly associated with the duration of transfer, while the problems of wear are predominantly associated with the frequency of transfer. These effects are compounded with the following. During some transfers more numerals index than during other transfers. The more numerals that index the more is the second moment that has to be accelerated and decelerated by the input during the duration of transfer. Thus, in an orthodox indexing counter the dynamics problems of acceleration (and deceleration) limit its speed to very low c.p.s. (count-per-second) values. Other conditions being the same, this limit is essentially a function of the duration of transfer and not of the frequency (or speed) of transfer. This frequency is usually in the range of from ten to one-hundred c.p.s. in orthodox indexing mechanical counters.

The foregoing considerations lead to the basic approach lof the high-speed register: to eliminate indexing mechanisms and to achieve counts of several thousand per second, midway between the capabilities of orthodox indexing mechanical counters :and those of electronic counters.

In the mechanism of FIGURES 1-9, the wheel 3 is driven so that it turns an angular distance equal to the ysequent second moment. jections.

width of one of its numbers at each transfer. This movement is here referred to as the excursion, which, -as stated, is relatively small and equal to one numeral-width pitch or, in contrast, the excursion in the C position becomes large. And the excursion in the D position would normally become exceedingly large for reasons to be brought out presently.

However, the present invention enables the numerals at the D position to share the lesser excursion of those at the C position, thereby holding the mechanism to an acceptably small size `and avoiding an excessive separation between the numeral positions. This result is achieved by combining the C and D positions .so that the C and D `numerals form a double Vnumeral that is equivalent to the hundreds and thousands numerals on an orthodox counter,because, for reasons to be covered below, the double numeral makes nine non-visible or useless transfers to one visible or useful transfer.

The specific high-speed register of FIGURES 1-9 is a mil-angle register (a special type of register: 6400 mils=360). FIGURE 2 shows this register .at the final transfer between 6399 and 0000.

Another advantage of combining the D and C numeral positions becomes evident now in this type of register. If the D numeral position were separate and if it transferred at the orthodox interval of 1000 counts it would have to index at I1000, 2000, 3000, 4000, 5000, 6000, and 6400 (=0000). All transfer increments are 1000 counts except the last, which is 400 counts. This unequal increment can be handled in slow, orthodox counters by the use of fenders and associated other special mechanization.

yBut such special indexing devices have no place in this high-speed register, where indexing is avoided.

Consequently, transferring at 100 count increments is preferable vbecause y6400 is devisible by 100 an integnal number `of times and no unequal increment results. Thus, between 6000 and 6400 there are only three useless transfers in the D position instead of the visual nine. The problem then becomes one of merely applying the correct numerals to the band 7.

The band 7 is :shown here las a single-loop, continuous band, shown in FIGURE 1 as a 180 twist Moebius strip, the familiar single surface of mathematics. A plain loop could have been used, but the Moebius strip halves the length of band required. Numerals are applied continuously around the Moebius strip, appearing on both top and bottom surfaces, since these surfaces are the same surface, being continuous with one another. The band 7 may be regarded as a wheel equivalent. However, an equivalent circular wheel would be excessively large in a production design 'and moreover as a high con- The band 7 avoids these ob- The band 7 has a circumference of 64/2=32 double numeral-width pitches (u') and is shown `as perforated along its edges and is retained in mesh with sprockets S and 9 (FIGURES 1 `and 22) by second mask means, here a plain single-looped display mask band 10. The sprocket S may be chain-driven as at 58 from the shaft 54 of the tens wheel 3, and the band 10 drives the sprocket 9 as well as retaining the band '7. This secondary function of the band 10 will be described lfirst. This band is perfor-.ateo like the band 7, but has a circumference equal to thirty double numeral-width pitches, two less than that of the band 7. There `are no numerals on the band 10. The lesser length or circumference of band 10 produces a twopitch slack condition in the band 7, :and this slack is place-d on the bottom, unseen return stretch of the band 7 as a three-dimensional curl Within which the 180 Moebius twist occurs.

The primary function of the display mask band 10 will now be described, noting that the masks 7 and 10, for numeralpositions DC, are fundamentally different explained, combines the two functions of display and transfer, while the mask means 7-'10` is concerned with display only.

As Vmentioned before a Wheel could have been used in the DC position, but Would have been too big. By the same token a mask like means 6 (combining Vdisplay and transfer) could have been used for DC, but would have had to have a count cycle. This in turnwould have required a very large diameter tube 1 (which wouldV be required anyway to `go around the large assumed DC wheel). Size and second-moment considerations favor the mechanism shown in FIGURES 1-9 for the DC positions.

As a result the functions of display and transfer must be divided. Thus, mask band 10 performs the display Vfunction by exposing the desired double-numeraled numbers and covering the others. And additional masks 11 and 12, constructed on the tube 1 by axially spaced opaqued edges leaving a transparent area x, perform the transfer function. The masks 11 and 12 are essentially helical, having a lead of u, and follow the numerals on the band 7 in a thread-and-tooth relationship. The axial width of the opening X equals the excursion in the DC position. FIGURES l and 2 show the masks 1l and 12 at mid-transfer. FIGURE 4 schematically shows the masks 11 and 12 and the means 6 rotated about 90 from the position shown in FIGURES 1 and 2 to make a clearerpcture.

The masks 11, 12 differ from the means 6 in that they are single rather than the double-series type of the means 6 and accordingly turn only one revolution per twenty counts on the wheel 2, and thus will set up a transfer situation every twenty counts. However, as will be clarified below, the transfer is caused to occur four times ineffectively for every once effectively.

. Since the one-cycle masks 11 and y12 are a part of the tube 1 and thus rotate with the wheel 2 which is also `part of the tube the following rule holds:

lThe number of series of numerals on wheel 2 times the number of transfer attempts of the masks 11 and 12 per hundred counts equals ten N2 may equal 1, 2, 5 or 10. Respectively NT equal l0, 5, 2, or 1. The 1, 10 combination is a long mechanism. The 5, 2 and 10, l combinations are mechanisms in which d (FIGURE 1) is too large and the second moments of rotating parts are too high. The 2, 5 combination as shown seems like the best compromise.

Since the displayed numerals at the DC position must move across the opening x and hence through the distance x lbetween transfers, and since the interleaved DC numerals other than the displayed DC numerals must be obscured during the display for reading and for coaction at transfer with the transfer masks 11 and 12, reliance must be placed on the display function of the display mask band 10. For this purpose, the display mask band 10 is opaque except for a plurality of transparent openings 10a each essentially one pitch wide (equals u), spaced at increments of 5u, which is the width of the opening x between the masks 11 and 12. Thus, it is necessary that the circumference of band 10 be divisible by 5u an integral number of times. Since this circumference is 30u the rule is satisfied.

The double circumference of the band 7 is 32 2=64u- This means that the sixty-four double-numeraled numbers on the band 7 must be physically adjacent even though such numbers adjacent in the number series are separated 5u physically. All spaces on the band 7 are used without gaps and with an excursion greater than one (5u in this case) by interleaving FIGURE 7 shows schematically the numerals of the band 7 laid out developed in a column with long horizontal upper and lower lines indicating the ends of the cycle of sixty-four double-numeraled numbers. FIGURE 7 also shows schematically the display mask band 1b in its starting relationship with band 7, and it will be noted that numbers adjacent in the number series are displayed (full-line squares). See this display action also in FIGURE 6. On successive circuits of the display mask 10 (see dotted positions in FIGURE 7) the number series interleaves with itself repeatedly so that the numbers to 63 will occur consecutively in the counting process.

It is a necessary (but not a suicient) condition that the number of number-width pitches in one cycle of the band 7 be prime to the number of pitches in the excursion. In this case 64 is prime to 5. An excursion of either 3u or 7u might also have been used. Other numbers larger than 7 might theoretically have been used for this milangle register but would have yielded a larger but less desirable excursion.

At this point, and by way of clarification, it should be remembered that any numeral on the band 7 that is displayed through an opening or window 10a in the band 10 is constantly but slowly moving from right to left across the opening x between the masks 11 and 12 on the tube 1. Consequently, the displayed numeral, first appearing to the left of the mask 11, will ultimately disappear beneath the mask 12 and the next consecutive numeral will appear at the mask 11 and so on. The opening or window x is helical and of the prescribed width (5u) because of the axial spacing of helices of the masks 11 and 12, to establish proper timing of the disappearance of the old numeral and the appearance of the new numeral so as to avoid a situation in which the two numerals might be displayed concurrently or the converse situation in which disappearance of the old numeral might be premature.

The bands 7 and 10 in the reading area adjacent to the window mask 4 should be at minimum clearance with the bore of the tube 1 (see FIGURE l0) for minimum parallax with the masks 11 and 12. To accomplish this the bore of the tube 1 may be grooved for clearance with the teeth of the sprockets 8 and 9 as at 1a and 1b (FIGURE l). Furthermore, a lateral curl may be applied to the bands 19 and 7 (see FIGURE 10) so that these conform more closely with the bore of the tube 1. The masks 11 and 12 and distance or opening x must be located between these grooves to avoid refraction and parallax problems, and, as already noted, the areas of the tube 1 which afford the masks 11 and 12 are opaqued, as are the aforementioned grooves la and Ib.

The display mask band maybe made of transparent t plastic or lm, opaqued outside the display areas or windows 19a. Or the display mask band 16 may be of thin metal, for example, and its display areas 13a would be cut-out openings.

An alternative display mask and window means is shown in FIGURE 8. This means comprises a separate tube 13 inside of and concentric with the tube 1 and is journaled for rotation relative to the tube 1. It has a helix 14 and is shown as rotating in the same direction as the tube 1, although `this is not necessary. Reversal of the hand of the helix 14 reverses the direction of rotation required for increasing count. The tube 13 may be transparent but opaqued except at the helix 14, which leaves the helix in the form of a helical transparent opening or window. Preferably the tube 13 is of thin metal with a helical window opening as shown. Thus, minimum parallax is established between means 13, 14 and the bands 7 and 1@ and the transfer masks 11 and 12.

The display mask and window means 13, 14 rotates at a speed diiferent from that of the tube 1, turning 360 per one-hundred counts. As a result, the ends of the helical opening 14 move across the width W of the window 4 (see FIGURE 2) in about ve counts. Hence, means 13, 14 cannot be used for one-count transfer (as similar-type means 6 is) but can be used only as a display mask. The lead of the helical opening 14 is 5u (equals x) and the opening extends somewhat more than 363 so that the displayed numbers at transfer will remain unobscured by the means 13, 14 while the displayed numbers are operated on by transfer masks 11, 12. In short, the relationship between the helix 14 and the numerals on the band 7 is one of thread-and-tooth as in the case of the relationship of the means 6 to the numerals on the wheel 3 but at a different ratio.

Only the operating helical profiles of the masks 11, 12 are shown in FIGURE 8, and it should be observed that these profiles are not on the tube 13 but are outside of and around the tube 13 and on the bore or tube 1.

Both means 11, 12 and 13, 14 are shown at transfer in FIGURE 8 but rotated 90 as if stationary mask 4 were on the side toward the observer. The pronounced helix angle of opening 14 suggests that the displayed numerals be inclined to match the display opening. The advantages of display means 13, 14 are reliability and long life under severe ambient conditions.

Substitution of the alternative display means 13, 14 for the display mask band 111 means that some other means must be employed to hold the band 7 in mesh with sprockets 8 and 9, such as retaining rollers (not shown). Means should also be provided for holding the upper stretch of the `band 7 taut in the reading area. This can be done by suitably timed gearing or equivalent means between the sprockets 3 and 9 so that they are forced to rotate together with the upper stretch of the band 7 taut. This gearing would replace the chain-drive action of the band 10 as presently employed.

Whichever display-mask mechanism is used, all parts comprising the cooperating components at the DC position are driven at a geared relationship such as that shown in FIGURE 22, with the input such that the excursion at the DC position occurs in counts and transfer in one count.

If it is desired that the visual display of the highspeed register simulate an orthodox counter (not an odometer) in which the numeral in position A indexes, then the optical device of FIGURE l0 may be added. A regularpolygon prism 15 having an even number of sides is located immediately above the wheel 2 and is journaled to rotate on its prism axis. This axis is essentially parallel to that of the tube 1. Gearing or equivalent means (not shown) from the input rotates this prism at one facet per numeral (or per count on the wheel 2. The eye e looks through opposite parallel sides of the prism. By properly sizing the prism, the flat-plate refraction effect of opposite faces can cause the corresponding moving numeral on wheel 2 to appear to stand essentially still. Transfer takes place during the transit of one edge of the prism 15 across an opening q in a mask 16. If one-half a facet rotation carries a prism edge across 61, then transfer is in one-half count. And if the angular width W were half the spacing between adjacent numerals on the wheel 2, then the transfers at numeral positions DC and B would also take place in one-half count and satisfy the rule for all numeral positions that duration of transfer can equal.

The appearance of transfer in FIGURE l() depends on whether the device is used as a viewer (as shown) or as a projector (not shown). In the former at midtransfer the edge of the prism acts as a divider and half of one numeral is seen above it and half of the other numeral below it. Both numerals maintain an apparently fixed position and are progresively cut off or revealed by prism rotation. Alternatively, if the numerals were illustrated and picked up by a projection lens or lens system located about where the eye e is in FIGURE l0, the numerals could be projected on a screen. Transfer would then appear as progressive vignetting out and vignetting in of old and new numerals respectively.

The mechanism of FIGURES l-9 was described as if it `were a mil angle register (6400l counts). It can also be used as a degree (and tenths of a degree) angle register. In this event the last transfer would have been between 359.9 and 0100.0 The high-speed register can also ibe used as a conventional four-digit register with its last transfer between 9999 and 0000. In these three instances the total length of a cycle on the band 7 is 641.1, 36u and 10011, respectively. For size considerations the vMoebius strip is preferred for 64u and 100u. But 36u may be a plain loop and as such will be intermediate in physical length .between the 64u and 1001i Moebius strips.

The mechanism of FIGURES 1-9 can be designed to suit all three conditions with minimum changes. But, while 64M and 36u are prime to an excursion of 5u, 10014 is not prime. While 64u and 100M are prime to 3u, 36u is not prime. But all three are prime to an excursion of 7u. Thus if x=7u the mechanism can be readily altered to cycle alternatively on 6,400, 360.0 or 10,000 counts.

The four-digit register of FIGURES 1-9 can be changed to a degree-and-minutes register. In order to assure transfer in a one-minute count, the tube 1 and wheel 2 should be, say, 60W circumference with each W unit marked off as a minute of arc. Thus, the wheel 2 would carry one series of sixty numerals from to 59. Similarly the means 6 must be changed to a single-series type and the wheel 3 must advance one numeral for each cycle (360 rotation) of the wheel 2.

The masks 11, 12, being of the single series type, will try to transfer once each revolution of the tube 1, or nine ineffective attempts for each effective atempt. Since the band 7 has thirty-six double-numeraled numbers (maximum count is 359`59) the excursion must be prime to 36, which indicates the selection of x=7u.'

In one revolution of the tube `1, the band 7 will advance .7a. Hence the pitch of the masks y1v1, 12 must -be less than u and will imperfectly mask the displayed numbers. Some tolerances of this sort can be accepted because the double-numeraled numbers do not completely fill the unit spaces u. Specifically, if they fill .7 of the space, the mask will just cover them except for parallax effects.

The foregoing achieves a one-minute-of-arc-count transfer as is required if the register always displays the correct numerical display even during the transfer operation.

Some larger number lthan 7 could have been selected prime to 36 to allow full masking effect of the transfer masks 11, 12, but this would have undesirably increased the excursion.

For 36 (or 64 or `100 as the case may be) to be prime to the excursion is a. necessary but not a sufficient condition. Thus, 36u is prime to 8u, but 8 re-enters after two circuits without interleaving and filling all spaces as is the desirable case shown in FIGURE 7, which suggests the following rule:

For an excursion of x units it takes x circuits of 4the band 7 (all circuits interleaving) before the number series re-enters itself at 00 and for a total band length of M units it is necessary and suicient that M, 2M, 3M etc. (x-l) M) all be prime to x.

Example l (for FIGURE 7): M =64 and 64, 128, 192, 256 are prime to 5.

Example 2 (like FIGURE 7 but x=7u): M =64 and 64, 128, 192, 256, 320, 384 are prime to 7.

Example 3 (for the degree-and-minutes register just described where x=7u): M=36 'and 36, 72, 100, 144, 180, 216 are prime to 7.

The mechanism of `FIGURES l-9 can be downgraded to a three-digit register by placing only the C numeral on band 7. This would reduce the value of u and consequently reduce the total circumference of band 7 to yield a more vcompact mechanism.

The configuration of FIGURES 1-9, in prototype and on the basis of present information, was best suited to a regular four digit` display.

`a long excursion and as such was applicable to a -mil- `best suited to a small excursion (in particular xp-Su).

Both and 64 are prime to 3. But 36 is not. Hence .this configuration is not suited to a degree-of-arc counter (different transfer masks could be used so Vthat a greater amount of the arcuate periphery of aband such as that kat 30 could be used, thereby making a degree-of-arc register possible. But such a mechanism would be a different configuration from that of FIGURES l1-20, common only in the sense that both use a display mask of the same'type as 30). However the configuration of YFIGURES 11-20 is compact and reliable in operation.

It may also be modified per FIGURE 21 into a simple three-digit register.

The detailed description follows. A transparent tube 21 (FIGURES 11-14) turns about its own axis with a gearedrelationship with the input'as in the case of FIG- URE 22. Y On an opaqued section on i-ts outer surface, f the tube 21 provides an A-position wheel 22 with three series of ten numerals. These numerals are read through a stationary mask 24 (FIGURES l2, 13). The wheel 22 may carry divisions at and between numerals (FIG- URE 12) and is read against a reader mark 25 on the mask 24 or on a transparent window (not shown) in the opening of the mask 24. There is a combination displayand-transfer mask and window means 26 (FIGURES 11, l2, 14). It is a three-cycle transfer means with the transfer points occurring at the 9.5 counts on the wheel 22. The means 26 is a transparent essentially helical opening on the opaqued bore of the tube 21, which has a groove 21a to provide minimum parallax between the means 26 and the barrel-shaped B position wheel 23. This wheel (FIGURES 11-13) carries preferably (for small size and consequent minimum numeral separation in the display) one cycle of numerals. FIGURE 12 shows the wheel 23 at mid transfer between 9 and 0 numerals. The means 26 follows these numerals in a thread-and-tooth relationship. The wheel 23 rotates at a speed of one numeral per series of numerals on wheel 21 and turns on centers (not shown) carried by the framework of the register. Increasing directions of count are indicated in FIGURES ll, l2.

FIGURE 14 shows the means 26 schematically and rotated 60 from the transfer position shown in FIGURE llfor greater clarity.

The tube 21 tu-rns 360 per 30 counts. A separate coaxial tube 33 (FIGURES 11, 12, 14) turns at a rate of 360 per 331/3 counts and surrounds a DC position wheel assembly to be described. The opaqued bore of the tube 33 carries a helical, one-cycle, transparent window means or opening x' defined by opaqued transfer masks or means 31, 32 with a lead of u and is shown schematically in FIGURE 14. In this case, the width in excursion of the window x is 3u. The'means 31, 32 are shown rotated five counts in a decreasing count direction. The geared relationship between the tube 33 and the input is not shown. The transfer point on the means 31, 32 on the tube 33 lags that of the means 26 on the tube 21 in the position shown in FIGURE 14 by a small angle y because of the difference in rotational speeds of the tubes 21 and 33. The transfer divisions on the means 31, 32 line up timewise (and positionwise also if the numerals are read on a straight line as they are in this example-FIGURE 12) lonce every hundred counts in the middle of the window 24 as shown in FIGURE l2. The transfer means 31, 32 are in a groove 34 on the bore of the tube 33, and this groove is shaped for minimumparallax relationship with the outside diameter of the cup-shaped display mask means 30. Because of the sharp epesses ister. This surface of revolution conforms, at least in the area under the window in stationary mask 24, to the groove 34 in the bore of the tube 33 with a minimumpara-.llax condition. Openings 38 (FIGURES l1, 15) in the display mask means St) co-act with the transfer means 31, 32 at transfer. Mid-transfer is shown in FIGURES 11, 12.

The display mask means 36l turns x'=3u in 100 counts. The transfer means 31, 32 try to transfer every 331/3 counts but two of every three are ineffective. The means 51, 32 follow the motion of the numerals displayed in the openings 38 with a thread-and-tooth relationship. All transfers (positions B, DC) are one count if W equals "s (FIGURE l2) as measured angularly at the axis of tubes 21, 33 (actually s is shown in FIGURE 12 as slightly larger than W). The tube 33 is shown separated by a distance Z from tube 21 (FIGURE l2). This distance is shown large to clarify the illustration, but should be small in a real configuration.

A multiple-loop band or indicia means 27 (FIGURES 16, 18-20) is carried inside the display mask 30 and these two elements afford the aforemen-tioned wheel assembly at the D C. position. This band carries doublenumeraled numbers on its outer surface and perforations similar to those of the band 7 for mesh with sprockets 28, 29, being confined to the sprockets by the bore of the display means 36. The sprocket teeth project through the perforations of the band Z7 into matching perforations in the display means Sti. Driving any one of the sprockets 28, 29 or the means 3th drives the other two and causes the band 27 to circulate endlessly via its return loops. These return loops can be held out of the way laterally by faces 36, 37 (FIGURE 20) on the sprockets 28 and Z9. rIhe position of these return loops can be further restrained to cross over the faces 36, 37 by idler rollers such as 3S (FIGURE 20) or a shaft extension 3% (FIGURE Ztl).

The looped coils of the band 27 (see FIGURE 18) produce a configuration having a lateral thickness "t projecting into the deeper part of the cup-shaped display means 30. Since this part of the cup shape is a lesser diameter, the guiding eifects for the band 27 shown in FIGURE 20 secondarily serve to reduce the diameter of the loops of the band so as to better fit the lesserdiameter parts of the display means 3h.

The double-numeraled numbers on the band 27 are not shown in FIGURE 18, but are shown in FIGURE 16. These numbers occupy sixty-four contiguous spaces, each having a width u, and have an excursion of :6:31: and are interleaved as shown schematically in FIGURE 17. This number series .is shown in a row arranged in two tiers because of its length. Adjacent to and above the number row are vshown schematically the openings 3d in the display means Sil. A complete developed cycle of band 27 and the display means 3h is shown between the long vertical lines in FIGURE 17 with the dotted parts continuing into adjacent cycles. It should be noted 'how the openings 33 progress into the next cycle in interleaved position and thence will account for all numbers in all spaces before re-entering the number series at OO.

FIGURE 21 shows how the mechanism of FIGURES 11-20 can vbe downgraded to a three-digit register. The display means Si) becomes an unperfor-ated wheel itl carrying one series of ten numerals (l, 2, 3, 4, 5, 6, 7, 8, 9, Each numeral occupies one unit space u and is separated from the adjacent units by 2u. The numerals may be wider than individual numerals of the .Lm double-numeraled numbers of the band 27. Or the wheel it? can be a lesser diameter than that of the means 3i), resulting in a lesser value for the unit pitch (11'). Hence the new excursion 4is x=3u. The wheel d is driven with a geared relationship (not shown) with the input, rotating about its own cylindrical axis at a rate of one numeral or three unit pitches in one-hundred counts. The wheel if? is shown hollow to reduce second moment. While it has been understood that the input to this high-speed register is a rotating shaft, that shaft can be preceded by other mechanisms. The input might he driven `by a ratchet actuated by coil or solenoid so as to accept an electrical pulse input. This mechanism would index or ratchet, thereby not being able to reach the high speed of a smoothly turning input. By the same token other indexing devices `could be used, some of which might be driven by reciprocating motions. The ratchet input could be replaced by an electric motor with a rotating field that drives a locked-in rotor. Each increment of rotation of the field could represent one count or integral fraction thereof. Thus, at low speeds the ratchet action would be essentially reproduced but the speed limitation of the ratchet would be eliminated. Thus, with suitable circuitry to change an electric-pulse input to a corresponding vector -direction of field high speeds may still be achieved due to the smooth-rotating effect of the field at high speed. The usual turning-shaft input of the high-speed register could be modified by the insertion of detented clutches or differentials. Both such mechanisms might allow, for example, that a manual rotation be fed into the register while the main input stands still. By this means counts could be fed into or abstracted from the register. rThis device amounts to a slow preset of any desired number into the register While the main input stands still. Since this preset number can be zero this device also serves as a slow reset. A detented (at the count) differential would permit there being more than one input to the register.

Essentially, the high-speed register or any low-torque instrument indicates a shaft position angularly. The input shaft might be driven by an isochronous device so that the register indicates passage of time. This combination of high-speed register with an isochronous drive is especially advantageous in comparison to the combination of an orthodox indexing counter with an isochronous drive. The former is a constant-torque, low second moment device, thereby not opposing the isochronism of its drive. These features are especially important to isochronous devices. In contrast the latter is of variable torque and variable second moment depending upon whether the mechanism is indexing and upon how many positions are indexing.

It is understood that the transfer and display masks and equivalents can take other forms--disks, for example. The simplest Version of the high-speed register is two interacting disks in adjacent parallel planes. These disks carry numerals and masks and interact to give the same action Aas described for the mechanisms illustrated. Difficulties are size, second moment, and curved numeral display.

The configurations illustrated are preferred and (so far as they go) duplicate the corresponding functions of orthodox indexing mechanical counters without their low speed limitation.

What is claimed is:

l. A high-speed register, comprising: a support; a hollow cylinder journaled on the support and rotatable about its principal axis; wheel means carried by the support within the cylinder and rotatable about an axis transverse to the cylinder axis, said wheel means including a peripheral portion having circumferentially spaced indicating marks thereon; window means carried by the cylinder and rotatable therewith and having a starting portion initially positionable in register with and enabling viewing of at least one of the wheel means marks through thecylinder wall, said Window means extending circumferentially about the cylinder wall in the form of at least-a portion of athelix about the axis of said 'cylinder and of such lead andpitch relative to the cireumferential spacing of the marks on the wheel means that, when the Ywheel means and cylinder are rotated continuously and uniformly-about their respective axes, ysaid kwindow means moves both axially and angularly to keep up -with said one mark on the wheel means so as yto remain in register with said one mark during a "predetermined extent of such rotation; and said window means having a transfer portion spaced circumferentially 'of the cylinder from said starting portion and offset axiallyfom the thread of the helix by an amount substantially equal to V-tlie circumferential spacing between `two adjacent marks on the -wheel means and operative when said lpredeterminedextent of rotation is exceeded to expose awheel means mark other than said one mark; and drive means interconnecting the cylinder and wheel means for rotation of the two as aforesaid.

2. The invention defined in claim 1, in which: said Awindow means is extended circumferentially of the cylinder from said transfer portion as at least a portion of a second helix about the cylinder axis and similar "'to and of the same lead and pitch as the first-mentioned helix portion and operative lto retain register with said other wheel means mark during rotation of the cylinder and wheelmeans through further angular ranges.

3. The invention dened in claim 2, in which: said 'second helix portion has a transfer portion similar to said `first-mentioned transfer por-tion and axially offset from the thread of its helix by an amount similar to the aforesaid amount and operative after a predetermined extent of rotation of the cylinder and wheel means through said further angular ranges to expose still another wheel means mark.

4. The invention defined in claim 3, in which: the Vtransfer portion of said second helix portion is axially alined with the beginning of the first-mentioned helix portion, each helix portion extending substantially 180 about the cylinder.

5. The invention defined in claim 1, in which: said window means is extended circumferentially of the cylinder from said transfer portion as at least a portion -of a second helix about the cylinder axis and of the Vsame lead and pitch as the first-mentioned helix portion so as to retain register with said other wheel means mark during a second stage of rotation of the cylinder and wheel means through further angular ranges; and said window means is further extended circumferentially of the cylinder from the .transfer portion of the second helix portion as at least a portion of a third helix about the cylinder axis and of the same lead and pitch .as the first and second helix portions so as to retain register with a subsequent third mark on the Wheel means during a third stage of rotation of the cylinder and wheel means through a still further angular range.

6. The invention defined in claim 5, in which: the transfer portion of the first-mentioned helix portion is axially alined with the beginning of the second helix portion, the transfer portion of the second helix portion is axially alined with the beginning of the third similar helix portion, and the transfer portion of the third helix portion is axially alined with the beginning of the firstmentioned helix portion, each helix portion having an angular extent of substantially 120 about the cylinder.

7. The invention dened in claim l, in which: the internal surface of the cylinder has a groove therein following said window means, said groove in cross-section being arcuate about the axis of the Wheel means, and the peripheral portion of the wheel means is transversely arcuate about the axis of the cylinder whereby the yperipheralportion of the wheel means is closely concentrically proximate to the groove to minimize parallax.

8. The invention defined in claim l, including: a circumferential series of indicating marks arranged about the cylinder and adjacent to the window means -for cooperation with indicating marks of the Wheel means as exposed by the window means.

9. The invention defined in claim S, including: fixed second window means carried by the support to expose certain of said marks of said series; and a rotatable prism carried by the support externally of the cylinder and generally on a radius extended from the cylinder axis and through said second window means.

l0. A high-speed register, comprising: a support; a first member movable unidirectionally along `a first delined path; a second member movable relative t-o the first member and unidirectionally along a second defined path transverse to the first path, said second member having indicating marks thereon spaced along said second pat-h so that upon advance of said second member in its path successive marks traverse the irst path; and window means on the first member having a starting portion initially in register with a certain mark and an elongated trailing portion `disposed oblique to said first path so that upon uniform continuous movement of the members as aforesaid along their respective paths and at a fixed ratio the trailing portion of the window means remains in substantial register with and exposes said certain mark for a period determined by the length of said trailing portion, said trailing portion termainating as a transfer portion offset transversely to the first path and lengthwise of the second path in an amount substantially equal to the spacing between tw-o adjacent marks on said second member and operative upon said movement beyond said period to expose a mark on the second member other than said certain mark; and drive -means interconnecting and driving said members at said iixed ratio.

ll. A high-speed register, comprising: a pair of members movable relative to each other and respectively along intersecting paths, one of said members having indicating marks spaced thereon along its path and the other member having window means therein oblique to its path and operative to expose certain of said marks in consecutive order; driving means connected to said members and including fixed-ratio mechanism operative to move the members relatively along their respective paths at a fixed ratio and continuously for advancing the marks on said one member in traversing relation to the window means; and said window means extending oppositely to the direction of movement of said other member and having such configuration relative to the spacing of said marks as to expose at least one mark for a predetermined period of said movement, said window means having a transfer portion positioned on said other member generally coincident with the expiration of said period and operative subsequent to said period to expose a mark other than said certain mark.

12. A high-speed register, comprising: unidirectionally continuously moving indicia means having indicatng markings spaced apart thereon; unidirectionally continuously moving display means movable relative to the indicia means and including a window portion adapted to expose one of said markings and mask portions iianking the window portion at opposite sides thereof and adapted to cover markings at opposite sides of said one marking; and driving means connected to the indicia means and to the display means and including fixed-ratio mechanism operative to drive said indicia means and said display means in continuous relative motion at such fixed ratio that during a predetermined period of such motion the window portion exposes only said one marking and the mask portions cover said opposite side markings, said driving means and window portions being so constructed and arranged that in a subsequent period of such motion one mask portion covers said one marking, the window portion exposes one 3,0 opposite side marking and the other mask portion covers still another marking.

13. A high-speed register, comprising: a support; an indicia member movable on said support along a first defined path and having indicating marks thereon spaced along said path and successively advanceable as said member moves; display means, including mask means spaced apart lengthwise of said path and providing a window therebetween; means mounting the display means on the support for movement relative to the indicia member and along a second defined path intersecting the path of the indicia member, said display means having a starting position in which the window is in register with at least one mark on the indicia member and the mask means covers two marks respectively at opposite sides of said one mark; drive means connected to the indicia member and to the display means and including fixed-ratio mechanism operative to move said indicia member and display means continuously and uniformly along their respective paths; and said display means being shiftable generally along the path of the indicia member in addition to its continuous motion and in timed relationship to the advance of said one mark on the indicia memher so as to retain register between the window and said one mark for a predetermined interval, said display means being subsequently shiftable generally along said first path to cause the window to expose one of the masked marks while the mask means covers said previously exposed one mark and still another mark next adjacent to the one masked mark now exposed.

14. A high-speed register, comprising: a hollow cylinder rotatable unidirectionally on its principal axis; window means in the Wall of the cylinder and formed as at least a portion of a helix about the cylinder axis and extending circumferentially of the cylinder oppositely to the direction of rotation thereof and having a leading portion and a trailing portion; indicia means at least in part within the cylinder and movable relative to the cylinder along a path generally parallel to the cylinder axis, said indicia means having indicating marks thereon spaced apart along said path, at least one of which is initially exposable through the leading portion of the window means; means for moving the indicia means continuously and uniformly along its path to advance said one mark; means for rotating the cylinder continuously and uniformly about its axis to advance the window means both circumferentially and axially in timed relation to the advance of said one mark so as to follow and expose only said mark during a predetermined interval; and said trailing portion being spaced circumferentially of the cylinder from said leading portion and also offset axially of the thread of the helix in an amount on the order of the spacing between two adjacent marks and operative upon expiration of said interval to expose a mark adjacent to said one mark.

15. A high-speed register, comprising: mask means advanceable along a first defined path and including elongated window means oblique to said path; indicia means in juxtaposed relation to the mask means to be viewed in part through the window means and advanceable along a second path crossing said first path, said indicia means having indicating marks thereon spaced along said second path, at least one of said marks being initially exposed by the window means; and means for continuously advancing the mask means and the indicia means along their respective paths at a uniform ratio such that each increment of advance of said one mark is accompanied by a follow-up increment of the window means along the path of said mark so as to expose only said one mark through said window means, said window means being of predetermined length and operative to expose said mark for an interval corresponding to said length, said window means having a terminal portion offset transversely to its length and lengthwise of the second path and in the direction opposite to advance of the indicia means and in an amount on the order of the spacing between two adjacent ld marks for subsequently exposing an indicating mark adjacent to said one mark.

16. A high-speed register, comprising: indicia means advanceable along a first defined path and having indicating marks thereon spaced uniformly along said path; first display means juxtaposed relative to the indicia means and advanceable along a second path crossing the first path, said display means including a window therein having a starting portion of a width, measured along the first path, substantially equal to a plurality of indicating marks so as to initially rega'ster with an indicia means portion bearing said plurality of indicating marks, said window extending obliquely to said second path in a trailing direction as respects the advance of said first -display means and having a lead opposite to the direction of advance of the indicia means, said window being of the aforesaid width throughout its length and terminating at a terminal portion disposed in spaced relation to said starting portion as measured lengthwise of said window means and in said :railing direction; means for advancing the indicia means and the first display means at a constant ratio such as to retain the register between the window and the indicia means portion throughout the length of the window means; movable second display means juxtaposed relative to and cooperative with the indicia means to initially expose a certain indicating mark and to cover other of said marks on said registered indicia means portion; means connected to the second display means and operative in timed relationship with the advancing means to cause said second display means to travel with the indicia means so as to retain said exposure of said certain mark until the terminal portion of the window ultimately reaches the indicia means path, said timed means being thereupon effective to move said second display means relative to the indicia means to expose another indicating mark and to cover the previously exposed mark.

17. ri`he invention defined in claim 16, in which: the indicia means comprises a pair of spaced apart rotatable elements and a first belt trained thereabout and arranged so that a run of said belt constitutes the registering portion of said indicia means; the second display means comprises a second belt surrounding the first belt and tautly trained about said elements to present a run overlying the aforesaid rnn of the first belt; said second belt having windows therein spaced apart on the order of the width of the first-mentioned width of the first display means and each of said belt windows being of such size as to expose only a desired mark; and said first belt having a length in excess of the second belt so that a slack portion of said first belt occurs between the rotatable elements and between opposed runs of the second belt.

18. The invention defined in claim 17, in which: the first belt has a Moebius twist therein continuously occurring in said slack portion thereof so that said first belt is capable of bearing indicating marks on both opposed surfaces thereof.

19. In a high-speed register: a pair of spaced apart relatively rotatable elements; a first belt trained about the elements for travel through successive cycles and having such length that a slack portion thereof occurs between said elements, said belt having indicia portions spaced apart lengthwise thereof at a uniform pitch; a second belt surrounding the first belt and trained tautly about the elements for travel in successive cycles; drive means connected to and operative to drive the belts through said cycles; said second belt having Windows therein, each of such size as to expose only one of the indicia portions on the first belt, said windows being spaced apart along said second belt at uniform intervals equal to a plurality of the hist-mentioned pitch dimension so as to expose non-consecutively positioned indicia portions on the first belt; and said slack portion of the first belt affording a stepping action of the first belt relative to the second belt so that different indicia portions appear at the window openings 17 during each travel of said belts around said elements through successive cycles.

20. rfhe invention deiined in claim 19, in which: the i'irst belt has a Moebius twist therein occurring continuously in said slack portion; and indicia portions are pro vided on both opposed surfaces of said first belt.

2l. A register, comprising: support means; a tube rotatable about its principal axis on the support means; iirst indicia means on and circumferentially spaced about the tube; means on the support means adjacent to the tube affording a fixed reference element past which said indicia means progresses as the tube rotates; a wheel within the tube and rotatable on the support means relative to the tube on an axis transverse to the tube axis, said wheel having its peripheral portion bearing second indicia means; window means on the tube and extending circumferentially thereof adjacent to the first indicia means and through which at least a portion of said second indicia means can be viewed from the reference element in conjunction with the first indicia means; third indicia means Within the tube and spaced axially of the tube from the second indicia means and movable lengthwise of and relative to the tube; second window means on and circumferentially of the tube and generally alined with and spaced from the rst window means lengthwise of the tube and through which at least a portion of said third indicia means is viewable from the reference element in conjunction with the second indicia means portion; and drive means for rotating the tube and Wheel and for moving the third indicia means.

22. The invention defined in claim 21, in which: the third indicia means comprises an endless belt having a run travelling through a path generally parallel to the tube axis and viewable through the second window means.

23. A register, comprising: a support; a tube rotatable on the support about its principal axis, a wheel within and rotatable on the support relative to the tube on an axis transverse to the tube axis, said wheel having its peripheral portion bearing indicia means; window means on the tube and extending circumferentially thereof through which at least a portion of said indicia means can be viewed from outside the tube; another indicia means Within the tube and carried by the support for movement lengthwise of and relatively'to the tube; second window means on and circumferentially of the tube and generally alined with the rirst window means lengthwise of the tube and through which at least a portion of said other indicia means is viewable in conjunction with the indicia means portion on the wheel; and drive means for rotating the tube and wheel and for moving the other indicia means.

24. The invention defined in claim 23, in which: said other indicia means comprises an endless belt having a run travelling through a path generally parallel to the tube axis and viewable through'the second window means.

25. In a high-speed register; spaced apart support means; a belt trained about said support means and having iirst and second spaced runs extending between the support means and further having a length in excess of that required to tautly encircle said support means; said belt having indicating marks spaced apart lengthwise thereof at a uniform pitch; display means surrounding the belt and so confining same that the first run stretches tightly between the support means and the second run includes the excess length, said display means having a window and associated mask therein such as to expose only a desired mark on the first run of the belt; drive means for moving the display means about the support means in timed relation to the belt; and said excess length of the belt affording a stepping action of the belt relative to the display means so that as portions of said excess length become portions of the first run different marks appear at the window opening during travel of said belt and mask means around said support means.

26. The invention defined in claim 25, in which: the display means has a plurality of window openings spaced apart uniformly at intervals equal to the intervals between pre-selected pairs of said marks that have other marks intervening therebetween.

27. The invention defined in claim 25, in which: the belt has a Moebius twist therein; and indicating marks are provided on bothopposed surfaces of said belt.

References Cited in the tile of this patent UNITED STATES PATENTS 1,725,978 Dement Aug. 27, 1929 

